In medical appliances requiring connection of passages for liquid(s) to be used for infusion, transfusion, nutrient dosing or the like, the liquid passages (circuits) must be connected and disconnected as required, when sustainedly or momentarily causing a flow of the liquid(s), such as a liquid medicine, blood, and liquid food. In such a situation, it is known to attach a connection means for connecting the liquid passages to an intermediate portion of the circuit. Typical examples of the connection means include the one described in Patent Document 1.
The connection means (connector) includes a male connector section, a male lock section provided adjacent (correspondingly) to the male connector section, a female connector section, and a female lock section provided adjacent to the female connector section. When connection means having such a configuration are connected to each other, the male lock section on one side and the female lock section on the other side engage with each other in a locked condition, and the male connector section on one side and the female connector section on the other side communicate with each other to permit liquid to flow therethrough. At the time of releasing the locked condition of the connectors thus connected to each other, an operating piece (operating part) provided on the female lock section is pressed, whereby engagement between the lock sections is released, and hence the locked condition can be released.
Thus, in the connector according to the related art (described in Patent Document 1), one connector section is provided with one lock section, as mentioned above. Therefore, there is a concern that when, for example, the connector in the connected condition is grasped, the operating piece on the female lock section might be pressed by mistake, unintentionally resulting in release of the locked condition.    Patent Document 1: International Publication No. WO 2006/068211